(a) A public entity other than a state agency may prohibit a depository or an entity of which the depository is a branch from being the custodian of or permitted institution for a security the depository pledges to secure a deposit of public funds.
(b) A depository or an entity of which the depository is a branch may not be the custodian of or permitted institution for a security the depository pledges to secure a deposit of public funds by a state agency.